Red Hat Enterprise Linux Server 7.4 update for kernel

1) Race condition

EUVDB-ID: #VU19996

Risk: Low

CVSSv3.1: 7.2 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2019-11599

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition with mmget_not_zero or get_task_mm calls and is related to fs/userfaultfd.c, mm/mmap.c, fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c due to kernel does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.61.1.el7

:

External links

http://access.redhat.com/errata/RHSA-2020:0103

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.

2) Race condition

EUVDB-ID: #VU17555

Risk: Low

CVSSv3.1: 7.9 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-6974

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows an adjacent attacker to gain elevated privileges or cause a denial of service (DoS) condition.

The weakness exists due to exists due to a race condition that causes the kvm_ioctl_create_device function, as defined in the virt/kvm/kvm_main.c source code file of the affected software, to improperly handle reference counting. An adjacent attacker can access the system and execute an application that submits malicious input, trigger a use-after-free condition and cause a targeted guest virtual machine to crash, resulting in a DoS condition. In addition, a successful exploit could allow the attacker to gain elevated privileges on a targeted system. 

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.61.1.el7

:

External links

http://access.redhat.com/errata/RHSA-2020:0103

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

3) Use-after-free

EUVDB-ID: #VU19568

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-20856

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local attacker to execute arbitrary code on a targeted system.

The vulnerability exists due to a use-after-free error when the "__blk_drain_queue()" function in the "block/blk-core.c" file mishandles error cases. A local authenticated attacker can access the system and execute an application that submits malicious input, cause a use-after-free memory operation error and execute arbitrary code on the targeted system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.61.1.el7

:

External links

http://access.redhat.com/errata/RHSA-2020:0103

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Improper access control

EUVDB-ID: #VU15643

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-18281

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a local user to bypass certain security restrictions.

The vulnerability exists due to improper access restrictions to memory when performing TLB flushes after dropping pagetable locks with mremap() syscall, A local user can access a physical page of a stale TLB entry after ftruncate() syscall is called to remove entries from the pagetables of a task that is in the middle of mremap() syscall.

Successful exploitation of the vulnerability may allow an attacker to gain access to sensitive information, stored in process memory.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.61.1.el7

:

External links

http://access.redhat.com/errata/RHSA-2020:0103

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Permissions, privileges, and access controls

EUVDB-ID: #VU13369

Risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-10853

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists in the way Linux kernel KVM hypervisor emulates instructions, such as sgdt/sidt/fxsave/fxrstor. A local unprivileged user on a guest system can gain write access to kernel space on the same guest system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.61.1.el7

:

External links

http://access.redhat.com/errata/RHSA-2020:0103

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.